Firearm sight



J. C. GARAND Nov. 1 1949.

FIREARM SIGHT Filed June 7, 1946 Jmhn E. EuTurLd A VLMMXM Patented Nov.1, 1949 UNITED STATES PATENT OFFICE FIREARM SIGHT John C. Garand,Springfield, Mass.

Application June 7, 1946, Serial No. 675,126

(Granted under the act of March 3, 1883, as amended April 30, 1928; 3700. G. 757) 4 Claims.

The invention described herein may be manufactured and used by or forthe Government for governmental purposes, without the payment to me ofany royalty thereon.

This invention relates to an improved rear sight mechanism for firearms.

The components of those rear sights having means of adjustment forelevation and windage are subject to vibration and shock due to thefiring of the weapons on which they are mounted. This is especially truein the case of such firearms as are designed for automatic fire. As aresult, such rear sights and the components thereof tend to shake loosefrom the position in which they are intended to be fixedly set even tothe extent where disassembly is apt to occur. In such case thesecomponents are apt to become lost due to their small size. Moreover, dueto the number and size of these components, the problem of supplyingrear sight spare parts to the soldier in the field has been found to beexceedingly complex.

Another disadvantage of present art rear sights exists in the resultinginaccuracy of sighting encountered when the components thereof jarloose. For instance, any loosening of the elevating pinion will causethe peep aperture to hop up due to the shock of recoil and therebychange the adjustment in elevation to which the sight has been set.Obviously such change in setting cannot be immediately detected by theuser of the firearm.

Accordingly it is an object of this invention to provide means wherebythe small components of 'a rear sight may be assembled to form two majorassemblies and whereby such assemblies may be secured to a rear sightbase so that unloosening of the components from set positions will notinadvertently occur.

It is a further object of this invention to provide a rear sight whichwill withstand the shocks encountered in continuous or automatic firingof a weapon without jarring loose to destroy the accuracy of thesettings for elevation and windage.

It is a particular purpose of this invention to provide an improvedadjustable rear sight for a firearm of the type disclosed in U. S.Patent No. 1,892,141.

The specific nature of the invention as well as other objects andadvantages thereof will clearly appear from a description of a preferredembodiment as shown in the accompanying drawings in which:

Fig. 1 is a right side elevational View of the sight shown mounted onthe receiver of a firearm;

Fig. 2 is a rear end view of the sight;

Fig. 3 is a longitudinal cross-sectional view of the sight taken alongline 3-3 of Fig. 1;

Fig. 4 is a right side elevational view of the fixed base of the sight;

Fig. 5 is a rear end elevational view of the windage assembly;

Fig. 6 is a left side elevational view of the fixed base of the sight;

Fig. '7 is a rear end elevational view of the elevation assembly;

Fig. 8 is an exploded perspective view of the locking nut and washer ofthe windage assembly; and

Fig. 9 is a rear elevational view of the dog of the elevating assembly.

The rear sight of this invention consists essentially of a fixed base 2which may be formed as the integral part of the receiver I of a gun, amovable sight base 3 adjustable laterally by a windage assembly 4, and asighting member 5 supported by movable base 3 and arranged to beelevated or depressed by an elevating assembly 6. The details andfunctions of the fixed and movable bases 2 and 3 and of the sightingmember 5 are substantially identical to those described in U. S. PatentNo. 1,929,418, the improvements residing in the means for securing thecomponents of the rear sight into two distinct assemblies and in themeans for securing such assemblies to the fixed and movable bases 2 and3.

Fixed base 2 is provided with oppositely disposed supports I and 8apertured to receive respectively windage assembly 4 and elevatingassembly 6. A plurality of notches 9 are included on the exterior sideof support I radially disposed about the aperture therein. Similarlylocated and disposed are a plurality of serrations In on support 8.Notches 9 and serrations I0 provide means of yieldingly securing thesighting member 5 in any desired position laterally and vertically aswill be later shown.

The windage assembly 4 comprises a windage knob II, a locking nut I2cooperating with a lock washer I3, and a split ring retainer I4. Windageknob II consists of a knurled thumbwheel I5 and a body I6 of smallerdiameter provided with threads H at the outer end thereof. An axial holeextends through windage knob II and is counterbored at the thumbwheelend as shown at I8 to receive lock nut I2 and lock washer I3. An annulargroove I9 is provided within the interior of counterbore I8 and theinner face of thumbwheel I is provided with a radial series of detents20 for purposes to be explained.

Lock nut I2 is a short hollow cylindrical member threaded in theinterior thereof at 2| for a purpose to be shown. Two oppositelydisposed slots 24 are provided at one end of lock nut I2 to permit theuse of a suitable tool for turning such nut. On the other end of locknut I2 are provided two integral oppositely disposed lugs 25.

Lock washer I3 is provided with a substanially D-shaped axial hole 26 asshown in Fig. 8 and a pair of oppositely disposed notches 21. Both facesof lock washer I3 may be provided with notches 21 but in such case eachpair of notches is spaced substantially 90 degrees apart with respect toone another. Notches 21 are adapted to mate with lugs 25 on lock nut I2.

An annular groove 28 is provided about the periphery of lock nut I2 andsplit ring retainer I4 is placed within groove 28. When lock nut I2 andwasher I3 are inserted within counterbore I8, split ring retainer I4,first compressed slightly to permit such ring to enter counterbore I8,expands outwardly to engage annular groove I9. Thus lock nut I2 andwasher I3 are permanently but rotatably retained within windage knob II.

The elevating assembly 6 comprises a shaft member 23, an elevating knob29, a retaining Washer 30, a washer-like dog 3|, a washer-like spring32, and a screw 33 on which a split ring retainer 34 is fitted.

Shaft member 23 consists of a serrated head portion 35 and an axial bodyportion 36 havin a pinion 3I integrally formed thereon. One end of shaftbody portion 36 is threaded as shown at 22 and is longitudinally cutaway so as to be substantially D-shaped in section as shown at 58. Theserrated head portion 35 is provided with a hole which is internallythreaded as shown at 41 in Fig. 3 for receiving screw 33 andcounterbored at 38 for the clearance of split ring retainer 34.

Elevating knob 29 is provided with a series of indicia 39 for indicationof the elevation setting of sight member 5. A serrated thumbwheel 49 anda detent 4| are provided on knob 29. Knob 29 is hollow in shape and theinner wall is provided with an annular groove 42 for the engagement ofretaining washer 30. Two oppositely disposed longitudinal axial notches48 are also formed in the inner wall for a purpose to be shown.

The right side of washer-like dog 3| is provided with a plurality ofradially disposed serrations 43 which correspond to similar serrationson the outer surface of head portion 35 of shaft member 23 and engagetherewith when proper assembly is made. Dog 3| is provided with a hole44 which is tapered inwardly and acts as a stop for the head of screw33. On the outer circumference of dog 3| are provided two 01 positelydisposed integrally formed lugs 49 which are adapted to fit inlongitudinal notches 48 in knob 29, to prevent rotation of dog 3| whenscrew 33 is loosened.

In assembling elevating assembly 6, the washerlike spring 32 is firstplaced over body portion 36 of shaft member 23 adjacent head portion 35and then both are inserted into the hollow elevating knob 29. Anintegral inwardly projecting flange 46 at the rear face of knob 29 shownin Fig. 3 decreases the diameter of the hollow portion to less than thatof spring 32 and head portion 35 thereby providing a seat for spring 32.Dog 3| is next inserted within knob 29 with lugs 49 engaging notches 48.Screw 33 is then inserted through tapered hole 44 of dog 3| and a splitring retainer 34 is placed around a reduced diameter portion of screw 33just beyond the head thereof. Thus screw 33 can not be accidentallydisassembled from dog 3|. Screw 33 is then threaded into head portion 35of shaft member 23 and retaining washer 39 is forced into annular groove42 on the inside of knob 29 to complete the assembly.

For complete assembly of the rear sight, elevating assembly 6 isinserted through the aperture in support 8 of fixed base 2 and windageassembly 4 is inserted through the aperture in support I and overthreaded end 22 of shaft member 23. As lock nut I2 is tightened, lugs 25thereon engage the corresponding notches 21 on lock washer I3 and canonly be disengaged thereafter by exerting a counterclockwise turningforce on lock nut I2 by means of a suitable tool inserted in slots 24.Upon tightening screw 33, serrations 43 on dog 3| engage the similarserrations on head portion 35 of shaft member 23 thereby enablingelevating assembly 6 to act as a unit with locking nut I2. But sincelocking nut I2 is rotatable within windage knob II, adjustments forwindage and elevation can be made independently without one affectingthe other. Pinion 3'! on shaft member 23 meshes with corresponding teethprovided on the underside of sighting member 5 (not shown) to raise orlower such member according to the direction of rotation of knob 29.When windage knob II is rotated, sight base 3 will move transverselywith respect to fixed base 2 either to the right or left according tothe direction of rotation of knob I I.

Rotating the elevating assembly 6 will not cause loosening of lockingnut I2 therefrom since the threaded end 22 of shaft member 23 issubstantially D-shaped in section and is inserted through thecorrespondingly D-shaped hole 26 in washer I3. Upon being tightened, nutI2 is locked to washer I3 and is consequently locked to shaft member 23and resists loosening due to vibration of the firearm in use.

When the sight is completely assembled to the firearm, detents 20 onwindage thumbwheel I5 engage notches 9 on fixed base 2 and are held insuch position by the bias of spring 32. However, when a turning force isapplied to thumbwheel I5, detents 20 will cam out of notches 9 androtate past the raised portions therebetween until the turning force isstopped, whereupon alignment again occurs between detents 20 and notches9, the bias of spring 32 insuring positive setting of thumbwheel I5against vibration or jars to the firearm. In a similar manner, elevationknob 29' will be positively engaged against support 8 with detent 4|engaging serrations I0. Due to the fact that only one detent 4| isprovided on knob 29, positive alignment with serrations I0 is assuredregardless of the position of knob 29 when screw 33 is tightened.

Elevating knob 29 may be readily zeroed by loosening dog-securing screw33 which releases some of the compression on spring 32. As a result, dogserrations 43 will cam past the serrations on head portion 35 of shaftmember 23 as elevating knob 29 is rotated, since dog 3| is preventedfrom turning due to lugs 49 engaging notches 48. Thus detent 4| can bealigned with a zeroing mark 45 on fixed base 2 without disturbing thesetting of sighting member 5.

set-rte ROQM Thus there is here provided an improved rear sight forfirearm by means of which settings for elevation and windage can beaccurately made independently of one another and such settings will notbe disturbed by any vibration or shocks. Furthermore, the components ofthe rear sight are permanently held in two major assemblies whichmaterially simplifies the problem of supply in the field and eliminatesthe possibility of loss of parts encountered in prior art rear sights ofthis type.

I claim:

1. In a firearm sight having a fixed base, a movable base adjustablelaterally with respect to the fixed base, and an aperture memberslidably mounted in the movable base for movement therein along a pathhaving a vertical component, the combination of, an elevating memberjournaled in the fixed base and having a threaded shank endsubstantially D-shaped in section, a knurled windage knob journaled inthe fixed base opposite said elevating member and threadably engaged bythe movable base, said knob having a counterbore therein for rotatablyhousing a locking nut threaded on said elevating member shank end, saidlocking nut consisting of a hollow internally threaded body havingintegral locking lugs on one end and a tool engaging slot on the otherend, and a washer on said elevating member shank end, said washer havinga substantially D-shaped axial hole and a pair of oppositely disposednotches, all adapted and arranged whereby said locking nut lugs areengaged by said washer notches thereby securely locking said nut on saidelevating member shank end against loosening, and whereby rotation ofsaid windage knob for lateral adjustment of the fixed base isindependent of rotation of said elevating member for movement of theaperture member.

2. In a firearm sight having a fixed base, a movable base, and anaperture member slidably mounted in the movable base for movementtherein along a path having a vertical component, the combination of, ahollow knurled knob having an annular groove therein and an integralinwardly projecting flange, an elevating member having a counterboredthreaded axial hole for receiving a screw, said elevating member havinga head adapted to be retained in said hollow knob by said inwardlyprojecting flange, said head portion having radial serrations on theouter surface thereof, a washer-like spring confined in said hollow knobbetween said flange and said elevating head member, a washer-like doghaving radial serrations on the outer edge thereof for engagement withsaid serrations on said elevating memher head, said dog having a taperedhole therein, a screw having a tapered head insertable within saidtapered hole of said dog and threadably engageable in said threadedaxial hole of said elevating member, and a retaining washer adapted tobe forced into said knob and be retained in said annular groove wherebysaid spring, said elevating member and said dog are permanentlyassembled in said knob and whereby when said screw is tightened said dogacts as a driving member for said elevating member.

3. In an elevating knob assembly for a rear sight mounted to a fixedbase on a firearm, means for zeroing said sight in elevation comprising,a knurled hollow knob having oppositely disposed axial notches thereinand having indicia for indicating adjustments of elevation inscribedabout the outer periphery thereof, a detent on said knob aligned withone of said indicia, an elevating member having radial serrations on theouter surface of the head thereof, said head housed Within said hollowknob, a washer-like dog having radial serrations thereon adapted to matewith and engage said elevating member serrations, oppositely-disposedlugs on the outer circumference of said dog, said lugs adapted to engagesaid notches in said knob whereby rotation thereof effects rotation ofsaid dog, a screw adapted to releasably secure said dog to saidelevating member head, and a zeroing mark on the fixed base, all adaptedand arranged whereby when said screw is loosened said dog will be freeto rotate independently of said elevating member when said knob isrotated for alignment of said zeroing mark with said detent.

4. In combination with claim 2, a, split ring retainer adapted to extendwithin said elevating member counterbore and surround said screwimmediately in front of said tapered head whereby said screw whendisengaged from said threaded hole is loosely but permanently restrainedfrom disassembly with said dog.

JOHN C. GARAND.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,821,576 Potter et a1. Sept. 1,1931 1,929,418 Garand Oct. 10, 1933 2,004,951 Jensen June 18, 19352,078,858 Kuhn Apr. 27, 1937 2,406,011 Garand Aug. 20, 1946

